BBC contrarian top 10

There is an interesting, if predictable, piece up on the BBC website devoted to investigating whether there is any ‘consensus’ among the various contrarians on why climate change isn’t happening (or if it is, it isn’t caused by human activity or if it is why it won’t be important, or if it is important, why nothing can be done etc.). Bottom line? The only thing they appear to agree about is that nothing should be done, but they have a multitude of conflicting reasons why. Hmm…

The journalist, Richard Black, put together a top 10 list of sceptic arguments he gathered from emailing the 61 signers of a Canadian letter. While these aren’t any different in substance to the ones routinely debunked here (and here and here), this list comes with the imprimatur of Fred Singer – the godfather to the sceptic movement, and recent convert from the view that it’s been cooling since 1940 to the idea that global warming is now unstoppable. Thus these are the arguments (supposedly) that are the best that the contrarians have to put forward.

Alongside each of these talking points, is a counter-point from the mainstream (full disclosure, I helped Richard edit some of those). In truth though, I was a little disappointed at how lame their ‘top 10’ arguments were. In order, they are: false, a cherry pick, a red herring, false, false, false, a red herring, a red herring, false and a strawman. They even used the ‘grapes grew in medieval England’ meme that you’d think they’d have abandoned already given that more grapes are grown in England now than ever before (see here). Another commonplace untruth is the claim that water vapour is ‘98% of the greenhouse effect’ – it’s just not.

So why do the contrarians still use arguments that are blatantly false? I think the most obvious reason is that they are simply not interested (as a whole) in providing a coherent counter story. If science has one overriding principle, it is that you should adjust your thinking in the light of new information and discoveries – the contrarians continued use of old, tired and discredited arguments demonstrates their divorce from the scientific process more clearly than any densely argued rebuttal.

Ok but what about 2006 and 2007 being cooler than several previous years?

Using GISS data, 2007 is on track to be the 2nd-hottest year ever, second only to 2005.

And the idea that every year should set a new record is nonsense. Statistically, we expect most years *not* to set a new record since the “scatter” in annual averages is about five times as large as the trend.

Gavin, re 241. I’ll grant that you certainly know how to read NASA’s words better than most. But which “large changes seen in Arctic climate in recent years” that are now maybe not thought to be a result of GW were they referring to?

#252, Tamino, #2 worldwide, #1 for the Northern Hemisphere, despite all the heat required to melt all that extra Polar ice. Don’t know why there is a difference between the Met office and NASA, but do know (by observations in the Arctic) that NASA is right…

Wayne, you might find the difference in the models here (not sure, I think I recall that Met and NASA differ in how much data they incorporate concerning polar latitudes)http://curry.eas.gatech.edu/ARCMIP/

Arctic Regional Climate Model Intercomparison (ARCMIP) aims to improve the simulation of the Arctic regional climate in numerical models. The primary ARCMIP activities focus on coordinated simulations by different regional climate models and general circulation models. Output from these models are compared and evaluated using observations from satellites, in situ measurements and field experiments. The first ARCMIP intercomparison Project is using data obtained in 1997/1998 during the SHEBA (Surface Heat Budget of the Arctic Ocean) http://sheba.apl.washington.edu/.

#Andre 177
“So the bottom line is that the anthropogenic global warming hypothesis can be considered scientifically feasible if no-one is able to falsify it.”

Writing as a non expert …..
Although I am not a fully paid up Popperian , I don’t think that the above remark does justice to the falsification idea. Here are some thoughts:

1. Different theories are more or less falsifiable. Theories which are almost non falsifiable fall on the wrong side of Popper’s demarcation line which mean that he would describe them as non-scientific. That conclusion is subjective and may be controversial. Anyway my point here is just to consider some examples. The most falsifiable theory is one which claims to be exact. Examples are relativity , quantum mechanics or nearly exact laws like the conservation of energy or second law of thermod. In all these cases a tiny anomaly may not be acceptable and might falsify the theory.

2. Andre’s phrase “if no-one is able to falsify it” concerns itself with quite a different issue i.e. whether we can should worry about the theory’s predictions not whether the theory is scientific. Notice that I did not write whether the theory is “right” because that language has to be replaced with words like “well corroborated”

3. Applied science often uses approximations and has “loose joints” it is harder but not impossible to falsify than the basic theories just mentioned (called Gold Standard theories by Penrose) just mentioned. They can be typically easier to corroborate (and thus harder to falsify) because of the error bars involved. Engineering and climatology fall into this category. That does not mean that they are non-scientfic. But if a particular such theory has too many adjustable parameters (I am not saying that it does) it would make it that much worse from the standpoint of Popper. First principles theories are less flexible and hence more falsifiable. Thus in sold state physics you can esily fit the phonon spectrum of one solid by a bedstead model (lots of springs) provided you have enough parameters but it is preferable if you can start from first principles. In climatology an example might be clouds ; they are supposed to be hard to understand from first principles basic physics ; if they are parametrised it is important that this process does not provide too much freedom otherwise the “theory” would be reduced to curve fitting. This practice is not necessarily flawed; but it might restrict the applicability of the output. (Vague thought unfinished).

4. Comment 187 by Timothy Chase. Interesting. I prefer your examples to those rather trivial examples of auxiliary hypotheses given by Popper.

5. Falsifiability and climate models ? (here is where my amateurish approach might show through). Consider a projection of the warming by say 2030. What is this? I think that this might be better thought of as a singular statement not a universal one. i.e as prediction not a universal theory consisting of an infinite number of predictions. That would mean that the asymmetry between falsification and verification does not apply. Wait until 2030 amd see. Singular statemnts cane be verified as well as falsified. (Popper does discuss this sort of thing).

You can also think of this projection in terms of the falsifiability criterion but I don’t like the resulting argument . This is how it would go: You would need a whole pile of planets. You would have to interpret the climate model as a “universal synthetic statement” (sorry Popper’s jargon). The theory would apply to every planet. So having tested it on a thousand planets and found that it worked every time a skeptic could come along and say “climate change is not a fact; induction is not rigorous, the next time you use your model it might break down !

Perhaps a better argument would go like this: Test the model over one decade. Result is false.
Check that is data OK. Conclusion ; cannot use model for next 20 years . Definite conclusion.
OR result it true. Cannot be sure that model will work over 20 years but encouraged to try it. Conclusion now indefinite; this demonstrates the asymmetry principle.
It works again. Model is even more likely to be useful for next 20 years. This shows both the asymmetry and the practical value of the inductive method which most people use.

6. Falsifiability and initial conditions. Yet another complication. Climate change depends on the emissions and the aerosols etc. etc. Popper discusses all this as a mixture of singular statements (the data) and the universal statements (the theory). If a test on this fails what have you falsified? It could be the initial conditions , it could be the theory.

7. Consensus. (Not in the index of Popper’s book). In my view this is just another version of the induction problem. To be absolutely sure you need a consensus over an infinite number of publications. Logically impossible. But notice that the best approximation is a consensus at a late date i.e covering a lot of research.

Incidentally Keith’s statement in #11
i.e. “as a rule of thumb I’d say the scientific consensus is more
often wrong than right.”

should be restated as “… is more likely to be replaced by a contrary consensus within N years than to survive intact”

This version can tested, but as John Mashey has implied this generalisation would be more applicable to a young subject and some of the main conclusions concerning global warming are not young.

With apologies for saying the obvious in a long winded way. That is what discussions about Popper seem to involve. I think that the only point of significance is the obvious one that too many adjustable parameters can be dodgy.

I read the BBC article, and I had one question regarding number 7. Why do you not think that the skeptic’s view on this is correct? What does it matter if there is more CO2 now than there was before? If CO2 has always risen after temperature has, why should it be different now, no matter how much more CO2 is in the atmosphere?

Re #254: Rod, the badly phrased sentence you keep quoting was written by a NASA PR person who was trying to make the research results sound as important as possible (and also IMHO covering a little bit for the fact that the purpose of the press release was to announce new results appearing to show the reversal of the trend discussed in the April paper). The “large changes” refer to the AO itself.

Given the NASA revelation in the last day or two that the Arctic warming is mainly a function of current variability, there are a lot of people with egg on their face at the moment. I’d like to ask the poster of #8 to think about the same question he posed for John Christy… what do you think about the Arctic melt now?

[Response: Do you have a link? This is very unlikely to be true. – gavin]

I went and found a news source of the type that might lead somebody to misinterpret the study’s findings to such an extent. I found it on Fox, which was my first choice.

From the NASA press release it sounds like some people had speculated that variations in AO might be caused by GW. On google scholar I’ve been trying to find a study that makes that claim, but so far no luck. It would be interesting to find out just how strongly GW was presented as a possible cause.

The original post jumped to claiming the Arctic warming and melting is being caused by the reversals in Arctic ocean circulation, and not by AGW, or at least I think that is what he was saying.

if you read this carefully, I think you can see how the seeds for the weeds of misconception were planted by FOX:

Perfectly Natural

Many global warming activists point to changes in the arctic icecap as proof of the dangerous effects of man-made global warming. Now a report from NASA’s Jet Propulsion Laboratory says those changes are in fact the result of natural ocean circulation patterns. A team of scientists used satellite and deep-sea pressure gauge data to monitor ocean patterns.

Says team leader James Morison of the University of Washington’s Polar Science Center — “Our study confirms many changes seen in upper Arctic Ocean circulation in the 1990s were mostly decadal in nature, rather than trends caused by global warming.”

…

The study was done on Arctic oscillation and Arctic Ocean circulation, not the ice cap.

I thought this was the most interesting paragraph from the Nasa press release:

Morison cautioned that while the recent decadal-scale changes in the circulation of the Arctic Ocean may not appear to be directly tied to global warming, most climate models predict the Arctic Oscillation will become even more strongly counterclockwise in the future. “The events of the 1990s may well be a preview of how the Arctic will respond over longer periods of time in a warming world,” he said.

That old man AGW just keeps rollin’ along right back into the picture.

Thanks Hank, there has been a remarkable increase in Arctic temperatures
since the Sheba project. 1997-1998 marked the beginning of noticeable Arctic climate change, with every subsequent year having something new or unusual to behold. It got really stranger in 2004-2006 period when Arctic stations started to report unheard of near +10 C monthly anomalies, interspersed at many locations, making it obvious that the heat was on really strong at least in one region. It all culminated to the great melt of the summer of 2007. All in line with a substantial increase in tempertatures, not what was often said from contrarian sources, a levelling of the temperautre trend, nothing resembles to temperatures as usual here, every Arctic location was warming, assymetrically or at times the entire region simultaneously. A temperature anomaly chart not showing this growing trend should be seriously questionned.

All in line with a substantial increase in tempertatures, not what was often said from contrarian sources, a levelling of the temperautre trend, nothing resembles to temperatures as usual here, every Arctic location was warming, assymetrically or at times the entire region simultaneously. A temperature anomaly chart not showing this growing trend should be seriously questioned.

I am able to perceive depth only because my eyes do not see quite the same things. The differences between Hadley and Nasa can be useful so long as we keep in mind what they are. I presume Hadley wanted to preserve the continuity with the earlier historical record, and if so that may very well justify their approach.

I thought this was the most interesting paragraph from the Nasa press release:

Morison cautioned that while the recent decadal-scale changes in the circulation of the Arctic Ocean may not appear to be directly tied to global warming, most climate models predict the Arctic Oscillation will become even more strongly counterclockwise in the future. “The events of the 1990s may well be a preview of how the Arctic will respond over longer periods of time in a warming world,” he said.

That old man AGW just keeps rollin’ along right back into the picture.

Sounds to me like a classic case of projection…

If this picture were applicable to the real climate system, it would imply that anthropogenically forced changes in climate would project primarily onto the principal patterns of natural variability, even though such natural variability may occur predominantly on timescales much shorter than that of the imposed forcing.

[… and later]

On the basis of the approach presented here, it is possible that this bias is a response to anthropogenic forcing (recent model integrations confirm a strong effect of anthropogenic forcing on the Arctic Oscillation).

4. Comment 187 by Timothy Chase. Interesting. I prefer your examples to those rather trivial examples of auxiliary hypotheses given by Popper.

The argument is essentially that of Pierre Duhem. Duhem’s Thesis, 1892.

Preceded Popper’s first formulation of the Principle of Falsifiability by approximately 50 years, and if correct demonstrates that it is unworkable, strictly speaking.

*

However, I like the idea of a theory being “more or less falsifiable.”

In essence, one could reinterpret Popper’s Principle of Falsifiability along weaker lines and argue that it is a normative principle in accordance with which scientific theories out to be constructed so that they are as close to being falsifiable as possible. And what would this mean? That they should strive to make risky, specific predictions, where by “risky,” one means predictions such that if the theory is not correct, the predictions would have a small probability of being true.

7. Consensus. (Not in the index of Popper’s book). In my view this is just another version of the induction problem.

How about consciousness? What evidence do you have for distinguishing between what you are aware of and the you that is aware? But if such a distinction is not taken for granted, will it make any sense to speak of “theory” or “methodology”?

To be absolutely sure you need a consensus over an infinite number of publications. Logically impossible. But notice that the best approximation is a consensus at a late date i.e covering a lot of research.

Within the context of either induction or consensus, I don’t worry about being “absolutely sure.” This is the reason why I specifically conclude 187 with the sentence:

Third, in science, one must regard many statements as true even if the justification of these statements does not admit of absolute certainty. Much of our knowledge is corrigible.

*

But to approach this from a different perspective and setting aside Duhem for the moment, is the Principle of Falsifiability itself falsifiable? Would it be able to perform its role as a principle for the demarcation of scientific discourse from other forms of discourse if it were falsifiable?

Popper thought that other forms of discourse (e.g., regarding art, philosophy, or ethics) were meaningful. A good thing, too, since the Principle of Falsifiability would only appear to be able to perform its role of demarcation if it were either a universally recognized tautology (which it clearly isn’t) or a normative principle stating in essence how science ought to be done — which is of necessity not falsifiable.

*

In any case, I would argue that at any given moment, the individual is quite limited in terms of what they can articulate in words or thought. There is a great deal which they must simply take for granted in order to live and think in the world, a great deal which remains tacit. Their senses are part of their means of awareness, but so is their personal history, and so too is the society into which they were born and live.

Likewise, when formulating a test for a given theory so that it may be “testable,” generally there will be a great deal which must be taken for granted, assumed to be true. That is the consensus, and that is the function of consensus in science. Elements of the consensus may of course be brought into question and subject to tests, as well, but never the totality — except as a philosophic exercise.

*

This of course brings us back to Duhem’s thesis. Given the role of the consensus, science is fallible, but it can also be self-correcting.

Short answer : Because time and speed are of the essence in all dynamical problems. In addition the measured rise in CO2 has been shown to be man made and has not come out of the oceans as in the past (Discussed somewhere on Realclimate). Just one piece of evidence is that the oceans are not liberating CO2 now is that they are becoming less alkaline (acid ocean effect).

But the skeptics could end up by being right in a way which would not please them (or anyone else).

There are already signs that the oceans are taking up less CO2. If it gets much warmer these sinks could turn into sources just as they were in pre-history. The same could happen with other sinks. So some way down the line (centuries ?) it might once more appear that temperature changes lead CO2 changes. But that would not stop the physics; it would still be true that CO2 would create more warming. This double cause and effect happens in all positive feedback loops. The novel feature of that one would that it would have been initiated by humans in contrast to earlier ones which were started naturally (e.g by orbital changes of the Earth)

Incidentally Gavin’s introductory reply to the BBC on this point includes the word “irrelevant”. I don’t quite agree. The trouble is that quite a few well educated people have asked me about just this point (not the others) and they didn’t like the official answers they found on web sites(compare Ike above). This is because they had to choose between two incomplete accounts. Yes it is irrelevant to the attribution of recent warming but not to people’s view of the bigger picture. The lag is essential evidence for climatological theory not against it as argued in GGWS and elsewhere. I think the judge in the recent “Al Gore trial” in the UK was similarly irritated by too much abridging.

I wrote a longer answer (no doubt too long) which is available in Section 5 of the document at

(Incidentally I included an argument based on breaking down the CO2 into two terms one of which always precedes the temperature. So the statement that CO2 follows the T is never quite right; it depends on which of two terms is dominant)

Re 258. Ike, indeed rising temperatures will probably ultimately cause natural sources to rise–a positive feedback that may represent a point of no return for climate change. There is already evidence of this happening from peat bogs in Siberia. The difference is that most previous warming epochs didn’t start with greenhouse gas warming–the outgassing merely acted to intensify and prolong the warming event. Where the denialists err is in assuming that this means greenhouses can’t be a cause of warming.

Re 258 Ike. Again if you have seen an inconvenient truth which incidentely had been widely applauded amongst climate scientists for being very very accurate; you would have seen the graph for CO2 vs Temp over the past 650 thousand years. the two practically mirror each other..they are very chiral indeed! Ask gavin why CO2 leads temp as I’m not the best person to ask. The fact remains that CO2 and Temp are inseparable and one directly affects the other.

Just a question. are we sure this warming trend started with GHG-warming? if you look at more than a 30 year view, the current warming trend started in the early 1800s and really took off in the early 1900s. There was a modest colling from 1940-1970, but the warming trend is almost 200 years old where the CO2 rise didn’t really take off until the mid-1900s.

The 1940-1970 period was affected by unrestrained coal particulate emissions that were reduced in most of the industrialized nations after the 1970s. These emissions including sulfur dioxide have strong climate cooling properties, but have much shorter atmospheric lives than CO2. After the 1970s most of them “fell out” of the atmosphere but most of the CO2 didn’t and won’t for a long time.

Dean_1230, there is certainly some doubt about the origin of warming prior to ~1950. However, reasonable variations in solar radiation coupled with anthropogenic emissions can explain them quite will. Solanki has shown that even if you assume that ALL the warming prior to 1970 (I think) was due to solar activity, you can’t reproduce the warming since. Also, remember that forcing is logarithmic in CO2 concentration.

“… carbon dioxide (CO2) emissions from fossil-fuel use for the years 1751 to the present. The time series begins with 3 × 106 metric tonnes carbon (C). This initial flux represents the early stages of the fossil-fuel era. The CO2 flux increased exponentially until World War I. The time series derived here seamlessly joins the modern 1950 to present time series. Total cumulative CO2 emissions through 1949 were 61.0 × 109 tonnes C from fossil-fuel use, virtually all since the beginning of the Industrial Revolution around 1860. The rate of growth continues to grow during present times…”

The first half of the fossil fuel so far burned was burned before about 1970, when the Clean Air Act first limited dirty smoke from coal plants to some extent. The second half since 1970 has been burned somewhat cleaner, though the ‘third half’ burned in India and China is pretty dirty again.

Re#240: Chuck, thank you for your review of the great variety of those things I had in mind when I wrote the sentence immediately following the one you quoted (in #222), which reads, “Of course we add various systems that attempt to augment memory by inserting some sort of “objective” devices (thermometers) or systems (record keeping and adjustments) to counter the pure subjectivity of sense experience.”

Ray Ladbury. If you think “CO2 levels are up 33% since the start of the industrial era, there’s warming, it’s bad, and it’s caused by CO2 and we have to do something” is a detailed explanation of what’s going on, you’re certainly entitled to your opinion. Or were you not trying to disagree that land-use chaanges, aerosols and soot have an impact on climate as do CO2 and methane et al? Just to make myself clear: I am NOT trying to argue CO2 isn’t a forcing, since it is. Okay?

Wayne Davidson. Are you really trying to compare a substance measured in parts per billion to one that that’s measured in parts per million, and that aren’t similar in either behavior or chemistry? I’m not trying to dispute that GHG are a big part of what’s going on, I’m simply saying up that CO2 = higher temps is an incomplete picture of what’s going on, and ignoring all else is not particularly helpful either in understanding the big picture or influencing policy.

Barton Paul Levenson. I’m not misunderstanding anything, I agree with you when you say “unless some countervailing process is blocking it”. That’s my point about land-use changes, aerosols and soot and so on, and ignoring the GHG. Soot on ice makes it melt faster. Sulphur in the air reflects sunlight. Questions: How much energy does 100 ppmv extra CO2 create? How much energy do melting clouds absorb? How much energy does water chaning to water vapor absorb? How much energy does 1050 ppbv extra CH4 create? And so on and so forth.

So we model them and we get an idea of what the system is doing. And the system is not just 1 thing. Does anyone dispute that? What are we arguing about?

Jim Eager. I didn’t say it was a harmless trace gas, just that it was a trace gas. I’m not disputing its effects nor that we’re causing additional amounts of it. I’m simply saying there are other non-GHG factors to consider. That the half-life of methane is 7 years and it’s 20% of the radiative forcing is just as interesting as carbon dioxide etc, but ignoring the other factors is like ignoring the GHG. It’s a system.

David B Benson. I don’t disagree with you. I wasn’t trying to really discuss CO2 but since that is what everyone seems to focus, I used it. I could have said CH4 or O3. That’s not the point, it’s not all there is in the system. Let me boil down what I’m saying “There are other factors to consider besides GHG.” That’s it. Not trying to say component x does or does not do y. Does my bringing it up brand me as making an ideological point? Because I’m not. I’m just saying you can’t ignore the -0.2 to -0.8 W/m² radiative forcing range suphates, the +0.1 to +.04 of black carbon, or the effects of sea-salt aerosols and how they differ between the hemispheres. Do we really need to discuss the basics instead of the mitigation and adaptation strategies?

Or does anyone disagree with

While the radiative forcing due to greenhouse gases may be determined to a reasonably high degree of accuracy… the uncertainties relating to aerosol radiative forcings remain large, and rely to a large extent on the estimates from global modelling studies that are difficult to verify at the present time.

That’s all I’m saying. Sorry if it’s nonsense and misinformation to anyone. Or does everyone just like to ascribe motivations, talk past each other, and argue about the details?

Rothrock & Zhang, 2004, “Arctic Ocean sea ice volume: What explains its recent depletion?”http://psc.apl.washington.edu/zhang/Pubs/rothrock_zhang_2004JC002282.pdf
I quote:
“By separating the ice response into thermally and
wind-forced components we find that the thermal component
of the response shows the volume of both undeformed
and ridged ice rather steadily declining since the 1960s. The
wind-forced component unexpectedly does not exhibit a
decrease of ridged ice, but it does exhibit a highly varying
but continually decreasing amount of undeformed ice.”

Rigor & Wallace, 2004, “Variations in the age of Arctic sea-ice and summer sea-ice extent.”http://seaice.apl.washington.edu/IceAge&Extent/Rigor&Wallace2004.pdf
I quote:
“The transition to an Arctic Ocean dominated by
‘young’ ice occurred abruptly in 1989–1990 when the
AO-index was over 2 standard deviations above normal.
The reverse transition from present day conditions to a state
like that which prevailed prior to 1989, with large areal
coverage of old, thick ice, would obviously take much
longer…

…The winter AO-index explains as much as 64% of
the variance in summer sea-ice extent in the Eurasian sector,
but the winter and summer AO-indices combined explain
less than 20% of the variance along the Alaskan coast,
where the age of sea-ice explains over 50% of the year-toyear
variability. If this interpretation is correct, low summer
sea-ice extents are likely to persist for at least a few years.
However, it is conceivable that, given an extended interval
of low-index AO conditions, ice thickness and summertime
sea-ice extent could gradually return to the levels characteristic
of the 1980’s.”
Or they could go t’other way. ;)

And as I was reminded of this recently (here at RC) and it addresses a possible anthropogenic role in the AO behaviour: Shindell et al 1999 “Simulation of recent northern winter climate trends by greenhouse-gas forcing.”http://pubs.giss.nasa.gov/abstracts/1999/Shindell_etal_1.html
I quote:
“we use several different climate-model
versions to demonstrate that the observed sea-level pressure trends,
including their magnitude, can be simulated by realistic increases in
greenhouse-gas concentrations. Thus, although the warming appears
through a naturally occurring mode of atmospheric variability, it
may be anthropogenically induced and may continue to rise. The
Arctic Oscillation trend is captured only in climate models that
include a realistic representation of the stratosphere, while changes
in ozone concentrations are not necessary to simulate the observed
climate trends.”
(I’m sure I’ve read something more recent and better than that – but I can’t put my finger on it.

#265 Timothy Chase,
I’m not ignoring you’re earlier post – I just can’t think of an intelligent thing to say in response, so I’ll just drag my rhetorical knuckles – I still “like” theories to make falsifiable predictions.

#265 Timothy Chase,
I’m not ignoring you’re earlier post – I just can’t think of an intelligent thing to say in response, so I’ll just drag my rhetorical knuckles – I still “like” theories to make falsifiable predictions.

Not a problem.

I will emphasize the interdependence which exists between scientific theories, and strictly speaking this is incompatible with Popper. (See comment 187.) The emphasis I place upon a tacit expert consensus (comment 155) is an outgrowth of my recognition of this interdependence. However, like foundationalism, naive theories of induction focus on the role evidence while omitting the role of counterevidence, and we need to consider the role of both in the scientific method. Popper brought to our attention the role that counterevidence plays in the the scientific method and this insight should be preserved. We can do this by regarding falsifiability not as a matter of either/or but as a matter of degree.

You seem to already be doing this:

1. Different theories are more or less falsifiable. Theories which are almost non falsifiable fall on the wrong side of Popper’s demarcation line which mean that he would describe them as non-scientific. That conclusion is subjective and may be controversial. Anyway my point here is just to consider some examples. The most falsifiable theory is one which claims to be exact. Examples are relativity , quantum mechanics or nearly exact laws like the conservation of energy or second law of thermod. In all these cases a tiny anomaly may not be acceptable and might falsify the theory.

But in this case, it might be better to speak of testability rather than falsifiability, and disconfirmation rather than falsification. And then we would indeed be moving in the direction of “the Bayesian view of science” – as David A. Benson suggested earlier. (See 274.)

re 259, 260: Steve, you say that a PR guy got it a little less than technically accurate or puffed it up a bit. I guess I can accept that, though I would expect NASA to be much better at their PR than that. So be it.

JCH, I’m having trouble following your argument (not even totally sure which side of the fence….). But assuming you’re in support of the NASA piece you do a tremendous amount of tap dancing to get around the simple fact that, if the piece did not refer to ice melt then it simply got over-hyped by PR, ala Steve above. Blaming Fox for the “misread” is simply ludicrous. You try way too hard.

Since we’ll never know for sure the PR puffery sounds logical and I’m willing to let it be as kind of a no-op. Besides, this is detracting from a bunch of interesting posts in this thread.

Hank. By “yanking it out” I meant “treating it as a single un-related variable” or some such.

I do in no way dispute that (depending on source) it is 9-26% of the greenhouse effect, has a radiative forcing of about 1.49-1.83 watts per square meter, a global warming potential of 1 and a measured amount of almost 400 ppmv. Just like I don’t dispute that water in all its forms is 90% of the effect but that we can’t directly influence the concentration of water vapor. However, we do influence clouds, by the same mechanism by which we produce the CO2 etc. Don’t think 169 ug/m3 of particulates in Cairo Egypt has a bearing on anything there? If you want to talk about 33% more carbon dioxide, why not 150% more methane, about a quarter of the radiative forcing of well mixed GHG? Why leave off nitrous oxide and the chlorflorocarbons? Why not look at the 5 other things rather than burning fuel for transportation that create carbon dioxide? There’s more to worry about and other compounding factors here.

All I’m saying is CO2 doesn’t exist in a vaccuum. It’s disturbing to me that it’s accelerated from about a 1% a year to 3% a year since the ’90s, sure. If the percentages hold, and CO2 is 10% of the GE, then it’s gone from ~6% of the GE since the early 1800’s. Is it the only thing to be concerned with? No.

Ralph, CO2 is the variable that we have changed that has caused the problem. It stands to reason that by reversing those changes we would alleviate the problem with the least unanticipated, adverse effects. CO2 is the 2nd most important gas, and the only one we can reduce that will significantly reduce warming. CO2 is extremely long-lived, and other “knobs” we can turn are much shorter lived. We understand the physics of CO2, but much less so that of aerosols and other variables. Other “knobs” likely have other adverse effects. In short, everything we understand about climate suggests that by messing with the system any more than you have to, you will likely cause as many problems as you solve.

“.. the ‘alternative’ scenario will not be easy to achieve. It requires that the world begin to reverse the growth of true air pollution (especially ‘soot’ and the gases that control surface ozone, including methane) and also that we flatten out and eventually begin to decrease CO2 emissions.”

That’s just one example. There are many others in the current science.

You’re arguing against a strawman or a myth. Not the scientists, not those of us here who are just reading the science to try to learn, not even the trolls here, claim CO2 is the only variable.

If someone told you that writers at RC say CO2 is the only variable, they lied — setting up a game of “let’s you and them fight.”

Yes, I read that sentence, but you seemed to be dismissing, or trivializing, those measurements when you wrote “And those abstractions are far simpler than the reality of the experience of weather. They basically consist of temp, wind and humidity.” My point was that an understanding of climate is based on more than just temperature, wind, and humidity data. I would suggest, though, that a climate scientist’s understanding of climate as a physical phenomenon probably does not include “all the little variables like, how old you are, what you’re doing, and with whom, when you last ate, what you drank the night before, what you’re wearing etc.”

“Many global warming activists point to changes in the arctic icecap as proof of the dangerous effects of man-made global warming. Now a report from NASA’s Jet Propulsion Laboratory says those changes are in fact the result of natural ocean circulation patterns. …”

What changes in the arctic icecap (solid) have scientists been saying are caused by AGW? Perhaps the melting is one they had in mind. Can you agree to that?

Are they not saying the NASA report exonerates man-made global warming in causing dangerous changes in the arctic icecap by falsely stating the report says the cause of those dangerous changes is natural ocean circulation patterns?

The report says no such thing. The report is mostly about water, not ice.

Re: Rod B
Here again the matter is one of extent, sure there have always been periods where the artic ice cap’s thickness has varied, even the thickness of the ice and density. However if you take a graph and measure the extent of ice melt all over the world, greenland, antartica, patagonia, europe etc etc you will see an undeniable similarity in every one of them, sure some ice because of it’s density, latatide and altitude may take longer to melt than others..but I’d bet if you took a density mesurment of the ice at various depths of all these regions you will see a similar rate of change..one that the density is getting softer and softer. The changes at the artic mirrors what is happening in antartica, the italian and swiss alps, new zealand, siberia, lapland and greenland to name but a very few. You would have to have boulders in your head if you cant see an irrefutable connection between all of those. Back to ‘extent’…the extent of melting and the time frame NOW compared to the cyclical ripples of melt that have always occurred in time past is massive, ‘UNPRECEDENTED’. Those scientists on the artic out there in boats are constantly seeing huge chunks of ice come away that are thousands and thousands of years old..not the result of cyclical melting and refreezing..but eons old!

Et al: Here again is the direct quote from the Summary of the NASA report: “…The results suggest not all the large changes seen in Arctic climate in recent years are a result of long-term trends associated with global warming.” Now any non-convoluted person could easily see that NASA was referring to the most recently discussed Arctic phenomenon — ice melt [as seemingly supported by Lawrence in 288]. They could also easily accept with minimal fuss, maybe after an explanation, that NASA was talking about something else that was once contended to be a result of AGW but now is uncertain, or that NASA was referring to something totally different, or that NASA PR mis-spoke a bit. But accepting what NASA wrote is not what they wrote, or understanding what the PR public notice said requires a PhD in climatology is beyond the pale. Tap dance all you want, but it is what it is. It is no stretch in the least to see that almost anyone would naturally read it as Arctic ice melt, even if that proves to be incorrect.

I simply asked what NASA meant. I got two plausible, acceptable, and simple answers, one from Gavin (well, half an answer from Gavin). Why is everybody else so vociferously presenting these terribly complex defenses?

“The mean time series shows quite coherent structure. The mean series shows the Medieval Warm Period (MWP) and Little Ice Age (LIA) quite clearly, with the MWP being approximately 0.3°C warmer than 20th century values at these eighteen sites. …” – http://www.ncasi.org/publications/Detail.aspx?id=3025

Excerpt from an earlier abstract:

“These results suggest that 20th Century warming trends are plausibly a continuation of past climate patterns. Results are not precise enough to solve the attribution problem by partitioning warming into natural versus human-induced components. However, anywhere from a major portion to all of the warming of the 20th Century could plausibly result from natural causes according to these results. Six of the models project a cooling trend (in the absence of other forcings) over the next 200 years of 0.2–1.4 °C. …” – http://tinyurl.com/3xgtyk

I wasn’t alive during the MWP, and I don’t expect any of my progeny, or theirs, will live through it either. Professor Loehle seems to think I’m wrong.

Jim, I’m talking about the subject in general, not singling out people here, nor everyone. I started this with a rhetoical question. Why are those focusing on CO2 as if it’s the only thing in the system. I didn’t accuse you or Real Climate or anyone of saying it was. I take issue with blanket statements as if they were fact, when they’re made, by whomever makes them. There are some that do, right?

Barton, “causing most of the problem” is too simplistic. What problem are you talking about? I’m guessing the observed warming trend. What do you mean by most? I’m guessing more than 50%, which is true if you’re talking only about the GHG part of it (not including ozone). But what about pollution? Does carbon dioxide reflect sunlight like sulphur does? Does it make ice melt faster than soot?

It would be true to say that “CO2 is about 60% of the greenhous gas portion of radiative forcing.” or that “By itself, CO2’s radiative forcing equals that of the other anthropogenic greenhouse gasses and ozone.” You could also say “The radiative forcing of CO2 is about equal to the radiative forcing of the net anthropogenic component, if you remove every other factor.”

Would fossil fuel usage that created another 100 ppmv of CO2 (along with all the rest of the positive and negative forcings) result in more positive forcing on the net?
Would reduction in output and sequestration of 100 ppmv of CO2 change things and result in a net negative forcing or would the rest of the system adjust? Depending on how much reduction (everything else in the system would, theorhetically be reduced) and how much sequestration (which would only remove CO2), balanced against the chemical reactions of things with each other.

I don’t know. And I don’t care. The specifics are moot — the question now is how and what to implement to reduce anthro-GHG and pollution and how to spur that into action in an efficient cost effect way that gets results.

Rod, what is at issue is the implication that “change” seen in the Arctic are due to processes other than climate change. Both the press release and the Faux News report are vague wrt what changes they mean and are to be criticized for that. The implication of the Fox report–and the way the report was received in the blogosphere–were than AGW is not important in the polar regions–a statement contrary to fact.

Ray, Hank, then we’re in agreement. I’m simply stating there are other factors, not accusing anyone of claiming there’s not (except if they do!). It’s a statement not an argument. I’m not saying that the people writing here said that CO2 was the only variable. I’m saying it appears to me that in general it gets too much focus. Which in my opinion doesn’t advance the case for action.

The policy focus should be the sum of anthro-GHG in total and pollution (different effect, same basic cause), while factoring out whatever part of this is land-use changes (or at least acknowledging it contributes to climate change as well.)

Burning less fuel or cleaner forms of fuel (or using PVs, turbines, water), using new technologies to reduce the output of the dirtier forms of producing energy et al, halting deforestation, and the like, takes care of both the anthro-GHG and pollutant problems at the same time, and does not rest upon what the specifics are. If it makes sense, various components can be sequestered. As I said, the science is settled. It’s time to move on and frame the data and conclusions in terms of getting action done.

My belief is you talk about the net gain in radiative forcing, which results in warming temperatures, and what the climate, economic, and health effects are of both the warming and of the pollution created. Then you have policy discussions to determine the cost/benefit ratio of various actions to halt or reverse various aspects. Then you implement them. Because we know it’s warming and what’s causing it.

“Human activities—primarily burning of fossil fuels and changes in land cover—are modifying the concentration of atmospheric constituents or properties of the surface that absorb or scatter radiant energy.”

“Reporting in Geophysical Research Letters, the authors attribute the reversal to a weakened Arctic Oscillation, a major atmospheric circulation pattern in the northern hemisphere. The weakening reduced the salinity of the upper ocean near the North Pole, decreasing its weight and changing its circulation.

“Our study confirms many changes seen in upper Arctic Ocean circulation in the 1990s were mostly decadal in nature, rather than trends caused by global warming,” said Morison.

“While some 1990s climate trends, such as declines in Arctic sea ice extent, have continued, these results suggest at least for the ‘wet’ part of the Arctic — the Arctic Ocean — circulation reverted to conditions like those prevalent before the 1990s,” he added. …”